Apparatus for drilling wells



March 4, 1958 J. A. REID 2,825,534

APPARATUS FOR DRILLING WELLS Filed'Sept. 20, 1954 4 Sheets-Sheet 1 QM INVENTOR.

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APPARATUS FOR DRILLING WELLS March 4, 1-958- 4 Sheets-Sfieet 2 Filed Sept. 20, 1954 J. A. REID APPARATUS FOR DRILLING WELLS March 4, 1958 4 Sheets-Sheet 3 Filed Sept. 20, 1954 INVENTOR.

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March 4, 1958 J. A. REID APPARATUS FOR DRILLING WELLS 4 Sheets-Sheet 4 Filed Sept. 20, 1954 United States Patent APPARATUS FOR DRILLING WELLS James A. Reid, Barflesville, 0kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application September 20, 1954, Serial No. 456,911 3 Claims. (Cl. 2554.6)

This invention relates to apparatus for drilling wells. In another aspect, it relates to a drill bit of improved construction.

Heretofore, oil or gas wells have ordinarily been drilled in the earth by a rotary drill or by cable tools. In both of these drilling systems, a string of drill pipe has been used which extends from the drilling tool to the surface of the earth. In the case of rotary drills, this drill string transfers torque from a prime mover at the surface of the earth to the drilling tool at the bottom of the well. In drilling with cable tools, the drill string carries drilling mud to the bottom of the well, and devices have been proposed, depending upon friction between the drilling tool and drill string, to cause rotation of the bit as the drilling progresses. Such rotation of the bit is quite important to obtain a proper drilling action.

It will be evident that the use of such a string of drill pipe greatly increases the cose of the drilling operation. First, the cost of the pipe is a factor and, second, it is difficult and costly to remove a long string of pipe to repair or replace the bit. Where a drill-rotating device is attached to the drill string, it is necessary to provide a device for preventing reverse rotation of the drill string relative to the drill hole.

In accordance with this invention, I obtain rotation of the bit without utilizing a drill string by securing a rotator device to the drilling tool, for example, to the drill stem or drill bit. This device engages the formations defining the drill hole in such fashion as to cause a unidirectional rotation of the drilling tool. In this manner, part of the reciprocatory or vibrational energy applied to the drill bit is used to effect rotation thereof.

This permits a downhole prime mover to be used, which can advantageously be of the electromagnetic or magnetostrictive type, so that the drill string can be eliminated and the complete drilling apparatus suspended by a cable or conduit for carrying drilling fluid to the drilling area. Thus, the drilling tool can be removed merely by reeling in the cable or conduit without removing and disassembling a long string of drill pipe. Although the most advantageous applications of the present invention are to systems utilizing a downhole magnetostrictive or electromagnetic prime mover, it will be evident that, in some cases, the motive power can be supplied from the surface of the earth and transmitted through a cable to the drilling tool.

Accordingly, it is an object of the invention to provide well drilling apparatus of improved construction.

It is a further object to provide apparatus for obtaining rotation of the drill bit without the use of a drill string.

It is a still further object to provide a system where the prime mover can be located downhole with the drilling tool and suspended by a cable or flexible conduit.

Various other objects, advantages and features of the invention will become apparent from the following detailed description taken in conjunction with the accorn panying drawings, in which:

2,825,534 Fatented Mar. 4, 1958:

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Figure 1 is a vertical elevational view, partially in sec-- tion, of a drilling tool constructed in accordance with the invention;

Figure 2 is a vertical sectional view, partially in elevation, of a swivel unit;

Figure 3 is a perspective view of a drill bit constructed in accordance with the invention;

Figure 4 is a sectional view taken along the line 4-4 of Figure 3, looking in the direction of the arrows;

Figure 5 is a vertical elevational View of a modified form of drilling tool;

Figure 6 is a vertical sectional view, partially in elevation, of an electromagnetic prime mover;

Figure 7 is an enlarged vertical sectional view, partially in elevation, of a bit rotator device; and

Figure 8 is a sectional view taken along the lines 8-8 of Figure 7, looking in the direction of the arrows.

Referring now to Figures 1 to 4, inclusive, I have shown an elongated drilling tool 10 comprising a cylindrical drill stem 11 and a bit 12. Mounted within the drill stem 11 and protruding upwardly therefrom is a magnetostrictive driving unit or motor 13 which is secured by a swivel connection 14 to a flexible conduit or cable 15. When actuated in the manner hereinafter explained, the prime mover produces a vibratory movement of the drill bit.

Referring to Figures 3 and 4, it will be noted that the drill bit has a series of teeth 15 and openings 16, the teeth being defined by a series of flat surfaces 17 which are inclined at a small angle with respect to a plane perpendicular to the axis of the tool. Certain of the surfaces 17 have a recess 18, and a spring element 19, preferably formed from steel, has one end 1% thereof secured within each recess 18, as by a bolt 20, and its other end 1% protruding beyond the face of the associated flat surfaces 17.

As the bit descends and contacts the formation at the bottom of the Well in its drilling action, it will be evident that the strips or elements 19 are pushed inwardly toward the face of the drill bit and thereupon exert a force upon the drill bit tending to rotate it in a counterclockwise direction, as viewed in Figure 3. These elements, of course, exert no force tending to rotate the drill bit in the opposite direction and, hence, can be referred to as devices secured to the drill bit and engageable with the adjoining formation to cause rotation of the drill bit in one direction but not in the other direction.

As shown and preferably, the motor which provides the aforementioned vibratory drilling action is located at the bottom of the hole and forms a part of the drilling tool. In the embodiment shown, this prime mover in eludes an annular coil 22 mounted concentricallywithin the drill stem 11. Mounted within the coil is an annular core formed from a series of vertical strips or laminations 23 of magnetostrictive material which are attached, at the lower end thereof, to the drill bit 12 by a pair of heavy metal plates 23a, 23b and, at the upper end thereof, to a pair of heavy metal plates 24 and 25. An annular sealing device 26 is disposed at the top of the laminated core defined by the strips 23 of magentostrictive material. These strips are arranged to define a central passage 27 communicating with the openings 16, Figure 3, in the drill bit for the purpose of supplying drilling fluid thereto.

When the coil 22, Figure l, is energized by alternating current of proper frequency, the magnetostrictive elements vibrate and impart a vibratory movement to the drill bits 12 in the form of rapid and repetitive power impulses. V

The swivel 14 includes an adapter 30 bolted to the plates 24, and secured to a housing 31 by mechanism including roller bearings 32, 33, and a rotary seal 34.

This structure permits the drrlling'tool to rotate freely of said surfaces whereby, when the bit engages the ground, said spring elements are pressed inwardly toward the face of the bit and thereby produce a rotary force upon the drill bit.

3. A drill bit which comprises, in combination, an elongated cylindrical body portion having teeth formed in one end thereof, said teeth being defined by flat surfaces making a small angle with a plane perpendicular to the axis of said bit, certain of said surfaces having recesses formed therein, and a spring element mounted in each recess, each spring element having one end thereof secured to the drill bit within said recess and its other end protruding outwardly from said recess.

References Cited in the file of this patent UNITED STATES PATENTS 47,599 Lovegrove May 2, 1865 5 47,600 Lovegrove May 2, 1865 545,149 Carpenter Aug. 27, 1895 1,600,492 Schmidt Sept. 21, 1926 1,965,563 Bannister July 10, 1934 2,243,319 Ross May 27, 1941 10 2,672,322 Bodine Mar. 16, 1954 FOREIGN PATENTS 2,443 Great Britain Jan. 26, 1905 

